(a) Field of the Invention
The present invention is related to a puller, and more particularly to one that allows easy replacement of jaws depending on the conditions of work environment.
(b) Description of the Prior Art
As illustrated in FIG. 5 of the accompanying drawings, a puller of the prior art is applied in the replacement or assembly operation of a work piece by holding the circumference of work piece to remove the work piece by pushing a cylindrical rod against it.
The prior art is essentially comprised of a puller 7 having disposed at its center a threaded rod 8 and outwardly extending from its center three fixed arms 71; a connection holder 9 is provided at where below the puller 7; a connecting arm 91 extending from each fixed arm 71; a jaw 92 is pivoted to the terminal of each connecting arm 91; a spring 82 of the threaded rod 8 is inserted onto the puller 7; and a knob 81 is screwed to where above the spring 82. Accordingly, by turning the knob 81 to push against the spring 82, the puller 7 is driven to close in all three jaws 92 to grab the work piece.
In practice, three jaws are pulled to clamp the work piece and the knob 81 is adjusted to where appropriately to provide sufficient clamping force to three jaws; and the threaded rod 8 pushes against the mandrel to remove it.
However, in a confined space where the work piece is located, three jaws 92 are prevented from clamping the work piece at the same time, or any jaw 92 fails to exercise normal clamping as contained by the structure in the vicinity of the work piece. Therefore, the puller with three jaws must be removed and another puller with two jaws is needed. As a result, it's time and efforts consuming work to replace the puller. Furthermore, it takes extra room and money to have both of the puller with three jaws and another with two jaws.